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Shu-Fen Cheng Chi-Ying Lai Sheng-Jie Lin Chin-Yuan Huang 《Environmental monitoring and assessment》2014,186(1):375-382
Air-drying and oven-drying are pretreatment processes often used before testing and analyzing various soil characteristics in the laboratory. This study selected three kinds of soil, including red soil, entisol, and alluvial soil, and examined the variation of the Cr(VI) content and Cr bond forms in these soils during air-drying and oven-drying. The results show that when the soil is air-dried in natural environment, the Cr(VI) content decreases with air-drying time. On day 10 of air-drying, the Cr(VI) content in these soils is 22.8~47.9 % of the initial value. When the soil is oven-dried, the Cr(VI) concentration decays faster; on day 8, the Cr(VI) is no longer detected in these soil samples. When the Cr(VI)-contaminated soil is treated by air-drying and oven-drying, the Cr bond form converts into a more stable form. After oven-drying, the Cr mainly exists in Fe–Mn oxide form, organic bond form, and residual form. The air-drying and oven-drying pretreatment processes of soil reduce the Cr(VI) content and stabilize the Cr bond form. If the laboratory analytic results are applied to risk analysis or remediation strategy planning for chromium-contaminated soil, the toxicity, bioavailability, and mobility of Cr in soil may be underrated. 相似文献
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Yu-Hsiang Cheng Ben-Tzung Shiu Meng-Hsien Lin Jhih-Wei Yan 《Environmental science and pollution research international》2013,20(3):1537-1545
Information on the relationship between black carbon (BC) and particle number levels in urban areas is limited. Therefore, investigating the relationship between BC and particle number levels in different particle size ranges at an urban area is worthwhile. This study used an aethalometer and scanning mobility particle sizer to measure the levels of BC and particle number simultaneously at an urban roadside in Taipei City. Measurement results show that hourly BC levels are 0.62–8.80 μg m?3 (mean?=?3.50 μg m?3) and hourly particle number levels are 4.21?×?103–4.64?×?104 particles cm?3 (mean?=?2.00?×?104 particles cm?3) in Taipei urban area. The BC and particle number levels peak during morning (7:00–9:00) and evening (16:00–18:00) rush hours on weekdays. Low BC and particle number levels exist in the early morning hours. Time variations in BC levels are the same as those of particle number levels in this study, clearly indicating that BC and particles are likely released from the same emission source. Additionally, BC levels in the urban area are more strongly associated with ultrafine particle levels than with total particle number levels, particularly in the size range of 56–180 nm. According to measurement results, most BC in aerosols in urban areas can be in the ultrafine size range. 相似文献
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While the innovativeness and market potential of a new product is normally emphasized, its environmental impact is often neglected. Despite their ability to help designers reduce the environmental impact of products throughout their life cycle, many eco-design methods focus on the redesign of existing products, necessitating a more innovative design capacity. This work describes a novel model to accelerate the preliminary eco-innovation product design by integrating the advantages of case-based reasoning and the TRIZ method. Previous cases from a database support a novel design to satisfy functional performances under the CBR framework. The innovative principles and evolution patterns of the TRIZ method can enhance the design level of new products to achieve eco-innovation. Four eco-innovation concepts for a PC mouse demonstrate the effectiveness of the proposed model. 相似文献
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采场是煤矿生产的核心地带,而采场通风系统是确保采场作业安全,创造良好生产环境的重要环节。本文以采场风流流动及瓦斯运移理论为基础,通过现场试验、模型模拟试验及计算机模拟研究等方法,着重研究了中国常用的和有发展前途的走向长壁后退式U型通风方式、U+L型通曲方式、后退式Y型通风方式条件下采场风流流动及瓦斯运移规律。 相似文献
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电旋风除尘模型实验研究 总被引:9,自引:0,他引:9
本研究试图将电除尘器与旋风除尘器组合为一体,以求取得较高的除尘效率,并利用旋转气流实现自动清灰。本文介绍了切向进气直流式电旋风除尘的模型试验,通过实测不同工况下的除尘效率和压力损失,应用经典除尘理论,建立了相应的数学模型。 相似文献
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作者在对中国我人民解放军第47医院病建项目所产生的大气环境影响进行了医学秤价和影响,并在预测的基础上,建立了完整的环境医学影响廉政价方法,由于该评价方法完全尊循了国内现行大气环境影响评价的基本要求和程序,因此,它在今后的环境影响医学评价中净有广泛的应用。 相似文献